Soak the rajma in water for 12 hours or until they double in volume.
Once the rajma is ready, add them into the pressure cooker along with the water. Add salt and baking soda.
Cook the rajma over high heat for about 4 whistles, after that lower the flame and cook for further 10 minutes. Once done allow the pressure cooker to naturally cool down.
In the meantime, blend tomatoes to make a paste, set aside. Next blend the onion with little water, set aside.
In a kadhai, heat the ghee on medium flame. Add black cardamom, cinnamon sticks, cloves, peppercorns, cumin and ginger garlic paste. Fry for 2 minutes on medium flame and then add hing. Cook everything until the ginger garlic paste is cooked.
Add the onion paste, cook for 2-3 minutes. Add salt and continue to cook for 5 minutes or until onions are brown in color.
Add cumin, coriander powder, chana masala, kashmiri red chilli powder; cook all the spices for 3-4 minutes over low flame.
Next add the tomato paste and cook until it leaves the sides of the pan, cover the pan and continue to cook.
Once done add the rajma and the water, add 2 glasses of extra water. Cover the kadhai and continue to cook over low flame for 15 minutes.
After 15 minutes of cooking, add the date and tamarind paste along with chopped coriander and stir everything.
